#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>

const char* filename="log.txt";

int main()
{
  perror("perror!!!");

  //fprintf(stdout,"hello stdout\n");
  //fprintf(stderr,"hello stderr\n");
  //fprintf(stdout,"hello stdout\n");
  //fprintf(stderr,"hello stderr\n");
  //fprintf(stdout,"hello stdout\n");
  //fprintf(stderr,"hello stderr\n");
  //fprintf(stdout,"hello stdout\n");
  //fprintf(stderr,"hello stderr\n");
  //fprintf(stdout,"hello stdout\n");
  //fprintf(stderr,"hello stderr\n");

  //printf("hello printf\n");
  //fprintf(stdout,"hello fprintf\n");
  //const char* msg="hello write\n";
  //write(1,msg,strlen(msg));
  //
  //fork();
  return 0;
}
